dermorphin has been researched along with phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide* in 2 studies
2 other study(ies) available for dermorphin and phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide
| Article | Year |
|---|---|
Mu and delta opioid receptor regulation of pro-opiomelanocortin peptide secretion from the rat neurointermediate pituitary in vitro.
We investigated the ability of selective opioid agonists and antagonists to influence pro-opiomelanocortin peptide secretion from the rat neurointermediate lobe in vitro. The mu-opioid agonist DAMGO ([D-Ala(2), N-Me-Phe(4), Gly(5)-ol]enkephalin) significantly stimulated beta-endorphin and alpha-melanocyte-stimulating hormone release relative to controls early (30 min) in the incubation period. Similar effects on beta-endorphin secretion were observed with the selective mu-opioid agonist dermorphin. The delta-opioid receptor agonist DPDPE ([D-Pen(2,5)]enkephalin) weakly inhibited beta-endorphin secretion relative to controls while the kappa-opioid receptor agonist U50488 had no effect. The mu-opioid selective antagonist CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2)) inhibited basal beta-endorphin secretion while kappa- and delta-opioid receptor antagonists had no effect. Our data support a role for local mu-opioid receptor control of intermediate lobe pro-opiomelanocortin peptide secretion. Peptide secretion from melanotropes appears to be tonically stimulated by activation of mu-opioid receptors in the absence of intact neuronal innervation to the intermediate lobe. Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; alpha-MSH; Analgesics, Opioid; Animals; beta-Endorphin; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; In Vitro Techniques; Male; Oligopeptides; Opioid Peptides; Pituitary Gland; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin | 2000 |
DAMGO, a mu-opioid receptor selective ligand, distinguishes between mu-and kappa-opioid receptors at a different region from that for the distinction between mu- and delta-opioid receptors.
The structural basis of opioid receptors (OPRs) for the subtype-selective binding of DAMGO, a mu-opioid receptor selective ligand, was investigated using chimeric mu/kappa-OPRs. Replacement of the region from the middle of the fifth transmembrane domain to the C-terminal of mu-OPR with the corresponding region of mu-OPR remarkably decreased the binding affinity to DAMGO, while the reciprocal chimera revealed the high affinity to DAMGO. These results indicate that DAMGO distinguishes between mu- and mu-OPRs at the region around the third extracellular loop, different from the case of the distinction between mu-and delta-OPRs in which the region around the first extracellular loop is important. Furthermore, displacement studies revealed that the region around the third extracellular loop is involved in the discrimination between mu- and kappa-OPRs not only by peptidic mu- selective ligands but also by non-peptidic ligands, such as morphine and naloxone. Topics: Amino Acid Sequence; Analgesics; Animals; Cells, Cultured; Endorphins; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalins; Ligands; Molecular Sequence Data; Morphine; Naloxone; Oligopeptides; Opioid Peptides; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Recombinant Fusion Proteins; Somatostatin; Structure-Activity Relationship | 1995 |